Youngstock Disease: Sudden Death and Ill Thrift

What are the differentials for sudden death in the UK?

Anthrax

Blackleg (Clostridium chauvoei)

Cl. sordelli

Electrocution

Bloat

White muscle disease

Acute trauma

Plant poisonings (Yew, Rhododendron)

What type of bacteria is Clostridium chauvoei (blackleg)?

Large gram positive rod

Anaerobic

Describe the pathogenesis

Spores circulate in blood and settle in muscle tissue

Cause bruising of tissue

Fall in oxygen tension

Spores germinate

Digest muscle within fascia

Diffusion of toxin outside muscle

Death - often all you see is sudden death

Low morbidity high mortality

What ages are susceptible? What seasons?

All but peak 6-24 months

Summer/autumn

Clinical signs

Sudden death - PM change very bloated and blood at orifices

If alive:

• Severe depression - unwilling to move

• Anorexia

• Pyrexia, tachycardia, tachypnea

• Rumenal stasis

• Very lame

• Hot painful swelling of affected muscle areas

• Convulsions

What would you see on PM?

Welling

Subcutaneous edema and emphysema over site

Muscle blackened with gas bubbles

Classic sour odor

How do you diagnose?

Gross pathology at knackery or farm after ruling out Anthrax

or submit to diagnostic lab - smears, stain with fluorescent antisera, PCR

Treatment?

Very sensitive to penicillin

• Clinical cases: sodium benzylpenicillin IV very high dose

• In contacts: LA penicillin products

Prevention?

Vaccinate!!

Clinical signs of Cl. sordelii?

Abomasitis/enteritis

Sudden death

Clinical signs of Cl. Haemolyticum?

Sporatic/western areas

Hemoglobinuria, jaundice, hepatitis, sudden death

What PM findings will you see for electrocution?

Singe marks

Capillary congestion

Ingesta in mouth

Normal rumen content

What causes pasture bloat?

Legumes (such as clover)

How does this cause bloat?

Makes a stable foam in the rumen that blocks air from leaving for eructation

What sounds might you hear a cow with bloat making?

https://www.myinstants.com/en/search/?name=FART

Treatment?

Stomach tube

Anti-foaming agent (Simethicone, fairy liquid)

Can prevent with mineral oil in water troughs

What causes white muscle disease?

Selenium and/or vit E deficiency

Often just after turnout since they are getting more exercise

Clinical signs/pathogenesis

Lactic acid builds up and causes muscle damage

Found dead or very lame/stiff

Heart is included in this muscle damage and it stops → death

Treatment? Prevention?

P: Proper mineral balance in food

T: Supplemental selenium and vit E injection (act quick)

What toxin does rododendron have?

Andromedotoxin

What animals are susceptible to rhododendron toxicity?

cattle, sheep, goats, cats and dogs

Clinical signs?

Projectile vomiting (this is the only condition that causes this)

Intense abdominal pain

Ataxia, anorexia

Convulsions, trembling, collapse, death

Treatment? Prognosis?

T: Astringents/tannins (tea!)

Poor ☹ if recumbent probably just euthanize, if still walking like 50% chance of recovery

What species are susceptible to yew (Taxus baccata) toxicity?

Cattle, sheep, horses, goats

Clinical signs?

Can be sudden death

Onset variable (hours-days)

Excitation, agitation

Tympany

Depression

Death

Treatment?

Gastrotomy to remove leaves, symptomatic with tannins etc

How does grazing vs housed affect susceptibility to ill thrift?

Grazing usually has less infectious disease challenge

Housed has better opportunity for observation

Nutrition varies based on different factors for both

What ill thrift diseases are most often seen when housed?

Respiratory disease

Ringworm

Coccidia

Chronic bloat

Under/poor nutrition

What is the pathogenesis of botulism?

Affects motor neuron binding (at synapse) - prevents Ach release

Leads to flaccid paralysis

How do farms get infected with botulism?

Associated with use of poultry litter fertilizer

Big bale silage (poor fermentation)

Clinical signs?

Stiff, weak, wobble, progressing to recumbent

Dysphagia → can’t swallow water → manically thirsty

Tongue hangs out

Death from respiratory paralysis, cardiac failure, or dehydration

Diagnosis?

Eliminate other causes of paralysis

Epidemiological evidence of exposure

Submit dead to PM for toxin detection

Submit feedstuffs/suspect casual sources to lab for toxin detection

Treatment?

Supportive therapy: stomach tube with fluids and feed, move recumbent cattle frequently

Notify Animal Health Office - NOT a notifiable disease but issues with food chain safety

Control/prevention?

Remove contact with suspect source

Do not use poultry litter near animals

Vaccine available in Ireland but don’t really need it just manage the pasture well

What bacteria causes tetanus?

Clostridium tetani: anaerobe, toxin producing

Describe the pathogenesis of tetanus

Spore enter wound (castration, penetrating wound, etc)

Germinate in anaerobic environment

Produce toxin → local or systemic effects, spasmodic muscle contraction

Clinical signs?

Stiffness

Raised tail-head

Bloat

Hyperesthesia

Dysphagia

Longer duration of progression os signs

How do you diagnose?

Clinical signs and history of wound

Toxin in serum

Gram stain smears from wound

Treatment?

In early cases antitoxin in available but VERY expensive and hard to get

Antibiotics

Supportive care

Sedatives

In severe cases euthanasia

Prevention?

Hygiene around castration, calving, etc

Vaccinate!!!

What is the scientific name for ringworm?

Trichophyton verrucosum

How do you treat ringworm?

You usually don’t

Could use topical enilconazole

Can vaccinate (Bovillus Ringvac) and this is therapeutic at double dose

What causes chronic bloat?

Primary: GIT motility disorder, poor weaning management

Secondary: papilloma, other GIT/abdo/thoracic pathology such as multiple bouts of bloat or scour

But often don’t find the cause

Can be associated with chronic low rumenal acidosis - rumen is huge from being stretched multiple times

Treatment?

Full clinical exam

Trumen trochar - leave in situ for 3-4 weeks

Is chronic bloat something you see at housing or pasture?

Housing

What are the different types of papillomas?

BPV1 - Fronds

BPV2 - Head and neck

BPV3 - Smooth warts

BPV4 - GIT warts

BPV5 - “Rice grain”

*BPV4 + bracken exposure = GIT carcinoma

How do you treat and prevent papillomas?

Autogenous vaccine, fly control

Minor warts are self limiting but can use topical creams on teats if needed

What is degenerative arthropathy (OCD)?

Degeneration of cartilage and sub-chondral bone

Joint effusion and osteophyte production

Occurs in hip, stifle, and hock

Which animals are more predisposed?

Youngstock

Based on genetics, nutrition, and conformation

Symptoms?

Gradual, shifting, progressive lameness

Treatment?

Palliative (NSAIDs)

Euthanize

What animals are most prone to sporadic bovine leukosis (SBL) and which forms?

Juvenile < 6 mo (multi lymph node)

Youngstock < 2 years (thymus) - most common

Occasional adult disease (skin)

Clinical signs of thymic SBL?

CHF, bloat

So with CHF you’ll see brisket edema, distended jugular

How significant is bovine papular stomatitis (BPS)?

It is usually innocuous but zoonotic

Treatment?

None